Constructing a Dobsonian telescope at home.

Hi. Myself and my father are currently attempting to construct a 16" Dobsonian telescope ourselves. We are both new to this and have no experience constructing equipment like this. Has anyone else attempted to construct a Dobsonian or other telescope? I am having difficulty acquiring glass thick enough to make the parabolic mirror. Anywhere in Ireland seems to have a maximum thickness of 19mm glass (about 3/4"). Im not sure this is thick enough to prevent thermal expansion in a 16" mirror but I will probably settle for it as I am impatient and excited to get the project off the ground. If you have constructed your own, is there any advice you can give on things you would have done differently had you known from the start? Did you run into any snags along the way,or any advice at all would be helpful and appreciated.

thanks!

There are several people on these boards who have either built or restored telescopes, and I'm sure they will make themselves known. First I would say well done for considering this project
There is a lot of help also on "Stargazers Lounge" a British web site that operates like IFAS - but with a lot more members, I know they have a comprehensive site for telescope making
I would also say, you should also consider buying the primary, secondary and focuser and this could save you a lot of time. Polishing a mirror to the exacting standards needed (although possible) is a potentially long process after which you will still need to send it out of the country to have it coated!......everything is possible but wait for other comments and advice from more experienced members with more brain smarts than me

Declan

PS the glass in my own 16" is approximately 40mm thick

Tianman,

I previously built a 16" donb.
See this long thread:
www.irishastronomy.org/index.php?option=...2&id=48685&Itemid=40

Have a read of that thread and if you have any questions, just ask.

Photos can be seen in this powerpoint file here - a talk I gave a few years ago:
www.astroshot.com/Dob/dob.ppt

Michael.

dmolloy:There is a lot of help also on "Stargazers Lounge" a British web site that operates like IFAS - but with a lot more members, I know they have a comprehensive site for telescope making
I would also say, you should also consider buying the primary, secondary and focuser and this could save you a lot of time. Polishing a mirror to the exacting standards needed (although possible) is a potentially long process after which you will still need to send it out of the country to have it coated!

Thanks for the faith dmolloy! Stargazers lounge, Has that got anything to do with the Darragh O'Brien and Dr. Brian Cox show "Star Gazers?" Amazing show, it was on tonight and last night. I cant wait for the James Webb telescope to give some extremely deep field images of the edge of the observable universe! Sorry, I went off topic a bit there.Yes I will definately buy the secondary mirror and focuser. I cannot afford a new primary mirror as I am a recent graduate scientist and still unemployed : angry: . I assumed I could aluminize the reflective surface of the mirror myself? thanks for the help. I've contacted a lot of places and still had no help finding thick glass to use as a blank for the primary mirror.

michaeloconnell: Tianman,

I previously built a 16" donb.
See this long thread:
www.irishastronomy.org/index.php?option=...=48685&Itemid=40

Have a read of that thread and if you have any questions, just ask.

Photos can be seen in this powerpoint file here - a talk I gave a few years ago:
www.astroshot.com/Dob/dob.ppt

Michael

This is fantastic. I can see myself referring back to your information repeatedly over the construction process. I didnt get through it all as there is so much information there. The powerpoint presentation is brilliant. You have actually changed the picture that i have in my head of what my telliscope will look like. I'm keeping the file on my desktop for reference. thanks a million.

Actually Michael, I have a question. If you don't mind me asking, Where did you get that extremely impressive looking 16" mirror in the fancy suitcase? And how much did it set you back?